Starch foam microparticles for delivery of non-aqueous liquid to bees

Abstract

The present invention relates to starch foam microparticles having a porous structure, and which typically have a diameter of less than or equal to about 50 microns. The present invention also relates to novel uses for the starch foam microparticles in beekeeping and in the pharmaceutical, plastics and fragrance industries.

1 . A starch foam microparticle wherein:
 (i) the starch foam microparticle has a porous structure, and wherein   (ii) the starch foam microparticle has a diameter of less than or equal to about 50 microns (μm) at its widest point.   
     
     
         2 . The starch foam microparticle of  claim 1 , wherein the starch foam microparticle has a density that is in a range that is between about 0.14 g/cm 3  and about 0.34 g/cm 3 . 
     
     
         3 . The starch foam microparticle of  claim 1 , wherein the starch foam microparticle has a density that is less than of equal to about 0.32 g/cm 3 . 
     
     
         4 . The starch foam microparticle of  claim 1 , wherein the microparticle has a diameter at its widest point that is in a range that is between about 5.0 μm and about 0.1 μm. 
     
     
         5 . The starch foam microparticle of  claim 1 , wherein the starch foam microparticle has a diameter at its widest point of less than or equal to about 20 μm. 
     
     
         6 . The starch foam microparticle of  claim 1 , wherein the starch foam microparticle comprises a starch that is a plant starch. 
     
     
         7 . The starch foam microparticle of  claim 6 , wherein the starch is a plant starch that is a member selected from the group consisting of a cereal starch, a tuber starch and a legume starch or a combination of such members. 
     
     
         8 . The starch foam microparticle of  claim 6 , wherein the plant starch is member selected from the group consisting of a modified starch and an unmodified starch or a combination of such members. 
     
     
         9 . The starch foam microparticle of  claim 7 , wherein the plant starch is a member selected from the group consisting of corn starch, wheat starch, potato starch, rice starch and high amylose corn starch or a combination of such members. 
     
     
         10 . The starch foam microparticle of  claim 1 , wherein the starch foam microparticle is loaded with a non-aqueous liquid. 
     
     
         11 . The starch foam microparticle of  claim 10 , wherein the non-aqueous liquid comprises at least one oil. 
     
     
         12 . The starch foam microparticle of  claim 11 , wherein the at least one oil is an essential oil. 
     
     
         13 . The starch foam microparticle of  claim 12 , wherein the essential oil has mitocidal properties. 
     
     
         14 . The starch foam microparticle of  claim 13 , wherein the essential oil is member selected from the group consisting of cinnamon oil, thyme oil, clove oil, patchouli oil, wintergreen oil and tea tree oil or a combination of such members. 
     
     
         15 . The starch foam microparticle of  claim 10 , wherein the non-aqueous liquid comprises a pharmaceutical. 
     
     
         16 . The starch foam microparticle of  claim 10 , wherein the non-aqueous liquid comprises a fragrance. 
     
     
         17 . The starch foam microparticle of  claim 10 , wherein the non-aqueous liquid comprises a pheromone. 
     
     
         18 . A population of starch foam microparticles having a porous structure, a density that is in a range that is between about 0.14 g/cm 3  and about 0.34 g/cm 3 , and a diameter that is less than or equal to about 50 μm wherein,
 (i) the population of starch foam microparticles is loaded with a non-aqueous liquid by forming a mixture comprising the non-aqueous liquid and the population of starch foam microparticles, wherein 
 (ii) the non-aqueous liquid is present in an amount that is less than or equal to at least about 25% by weight of the mixture, wherein 
 (iii) the population of starch foam microparticles absorbs the non-aqueous liquid thereby forming a loaded population of starch foam microparticles, and wherein 
 (iv) the loaded population of starch foam microparticles is a free flowing powder. 
 
     
     
         19 . A population of starch foam microparticles having a porous structure, a density that is in a range that is between about 0.14 g/cm 3  and about 0.34 g/cm 3 , and a diameter that is less than or equal to about 50 μm wherein:
 (i) the starch comprising the population of starch foam microparticles is a an unmodified plant starch that is a member selected from the group consisting of corn starch, high amylose corn starch and wheat starch, or a combination of such members; and 
 (ii) the population of starch foam microparticles is loaded with an essential oil that is a member selected from the group consisting of cinnamon oil, thyme oil, clove oil, patchouli oil, wintergreen oil and tea tree oil or a combination of such members. 
 
     
     
         20 . The method of  claim 19 , wherein the essential oil is present in an amount that is about 25% the weight of the population of starch foam microparticles. 
     
     
         21 . A method for controlling  Varroa  mites in a bee colony, the method comprising:
 (a) loading a mitocidal chemical onto a population of starch foam microparticles, wherein the starch foam microparticles comprising the population of starch foam microparticles have a porous structure, have a density that is in a range that is between about 0.14 g/cm 3  and about 0.34 g/cm 3 , and have a diameter of less than or equal to about 20 μm, and   (b) feeding the bees the population of starch foam microparticles.   
     
     
         22 . The method of  claim 21 , wherein the mitocidal chemical is an essential oil. 
     
     
         23 . The method of  claim 21 , wherein the essential oil is present in an amount that is about 25% the weight of the population of starch foam microparticles. 
     
     
         24 . The method of  claim 22 , wherein the essential oil is selected from the group consisting of thyme oil and clove oil or a combination of such members. 
     
     
         25 . A plastic composite film comprising starch foam microparticles wherein the starch foam microparticles:
 (i) have an porous structure; and   (ii) have a diameter of less than or equal to about 50 μm at their widest point.   
     
     
         26 . The plastic composite film of  claim 25 , wherein the starch foam microparticles have a density that is in a range that is between about 0.14 g/cm 3  and about 0.34 g/cm 3 . 
     
     
         27 . The plastic composite film of  claim 25 , wherein the starch foam microparticles have a diameter at their widest point that is less than or equal to about 25% of the film thickness. 
     
     
         28 . The plastic composite film of  claim 25 , wherein the starch foam microparticles have a diameter at their widest point that is in a size rage that is between about 0.1 μm and about 5 μm. 
     
     
         29 . The plastic composite film of  claim 28 , wherein the starch foam microparticles:
 (i) have a diameter at their widest point that is in a range that is between about 100 nm and about 999 nm, and   (ii) are present in the plastic composite film in an amount that is less than or equal to about 50% on a weight basis.